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My new 521


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Went for the test drive and brakes feel great. No pulling just solid stops. But NOW something has either got in my gas tank? Water maybe? Fuel filter looks separated cloudy on the bottom with small chunks and the top with clear gas presumably, since gas weighs less than water. I only drove down my block before it started shitting out and barely got home. Pulled a plug and it looks dark and rich/ fouled.

Has anyone had similar leaks of water in their gas tank? We just had a foot of snow fall and the bed was covered in snow for 5 days

Any help would be great. Thanks

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What kind of gas are you using, and how long did it sit in the tank?

I found that when I drove down to LA from Vancouver WA that the first fill up I did in CA I had to re-time my engine, that is some mighty crappy gas they are selling down there.

If I daily drive my vehicle I use normal ethanol type pump gas, if it sits around only getting driven every couple weeks or less I use non-ethanol gas, as that stuff doesn't rust my tank when it sits around for a while, that shitty ethanol gas is hard on metal gas tanks.

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what happens is the clamp gets loose and dirt and water will get passed and run down the hose.


Privios owner had this proplem with my 521 and said everytime it rained gas tank gauge would go up(filling up with water)


dirt and water will get in and rust tank then plug idle jet with rust particles. So I always swap out the filer on 521s more often. 510s don't have this proplem and rarely change them out as tank is not in the elements

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That is what happens when this crap gas they sell sits to long, it separates, it can happen fast sometimes.

This fuel was in the tank for less than 6 months in the photo below, the truck had been sitting on the side of the guys house in the grass without being driven, we had to pull the drain plug on the tank and empty it, then fill it with fresh fuel, once that fresh fuel got to the carb it started, you can see that layer of water/alcohol on the bottom of the plastic tub, the engine would not run on that crap.






The trouble with this for me was that once it happened to my spare tank in my work truck I could not stop it from separating anymore, the tank started to rust on the inside because of that crap fuel, and any fuel I put in it after that was ruined almost right away, I gave up and removed the tank(spare/2nd tank) and now only have my primary tank, that way it only has fresh fuel in it all the time.

If your fuel isn't a rust/orange color then your tank is still good like the fuel from his tank above, but if even fresh fuel is an orange color, your going to have to drop the tank and seal it after cleaning it out, as the rust has started, and there is no stopping it, rust never sleeps, it's doing its thing 24/7.

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Pulled the truck in the garage. More like pushed it in cause we're leaving for Disney land tomorrow. Plan on draining the tank getting a fresh filter and checking the filler tube. Going to run compressed air back to the tank.

Should I worry about the carb or just drain it and shoot it with carb cleaner?

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Drained the tank today. About 4 gallons came out, about 1 ga. was water. Blew air back to the tank and drained the carb bowl. Sprayed the carb with carb cleaner to help evaporate any water inside the carb. Need to pick up a fuel filter and fresh gas and I can give the brakes a proper test drive finally. Still need to find the source of the leak but, for now it's covered in the garage and dry.

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Got it back up and running. Brakes feel good. Maybe a little more adjustment and bleeding.

Seems if I pump the brakes they get firm at a higher pedal height. If I'm cruising the first time I hit the brakes they go down a bit further

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"Seems if I pump the brakes they get firm at a higher pedal height. If I'm cruising the first time I hit the brakes they go down a bit further."


This is a very common problem with 521 trucks.  The wheel cylinders have only one port for fluid and air to go in and out of.  You have to allow the brake shoes, and springs to collapse the wheel cylinders, and push any air in the cylinder back out to the bleeder valve.  If you use a pressure or a vacuum bleeder, the exchange of fluid for air never happens in the wheel cylinders. 


Bleed the brakes manually, with two people.  The person under the truck has to open the bleeder, when the brakes are applied, and the pedal has to go all the way to the floor, and held there.  With the pedal on the floor, the person under the truck has to wait until all fluid (and air) flow stops.  Then close the bleeder.  Then the pedal can be let up, slowly, and pushed again.  Three full pumps, and refill the master cylinder.

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This screw was just sitting there not threaded. Too small a screw and probably why I was getting water in the tank

I can't seem to find a sending unit o ring anywhere in town. If I understand it correctly it should be a 2.75 inch o.d o ring. A service manual shows what looks like a flat type gasket on a 521 and a o ring type on a 620. i guess I'll pull it out and see exactly what size type it is. I'll need to find a larger screw that will actually tighten and seal too

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  • 3 weeks later...

My wiper blades sucked ass so I trimmed down a 20inch set I had. 4D8C6B9F-913C-4B3C-96B7-3BBC489407C8_zps

Took the new blades apart and used just the rubber. 0BD106C0-8C4D-4C8D-BEA5-EE7989D19DB9_zps

Saved the metal strips from the old blade so it would line up with the old arm. 1B99EBFC-84EE-4E38-82BC-D8C99657EF7A_zps

Just trimmed it to fit and slid them in.067E60DC-A761-4EC3-998B-91897493F270_zps

I used needle nose vise grips to squeeze the metal past the prong to get it out.

Now I can drive in the rain and only deal with my bad windshield!!

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